Show HN: I built a free AI prompts and rules directory (ctx.directory)

A developer launched CTX, a free, community-driven directory for AI prompts and “rules” where people can discover, share, and remix ready-made system roles, prompt templates, and behavior constraints. Entries in the library show up as composable blocks — e.g., system role, context, instructions, constraints, output format, and example user inputs — and range from creative writing and brand-voice guides to strict behavioral rules like an “Absolute Mode” that enforces blunt, directive responses. The site emphasizes remixability and community curation, so builders can adapt, test, and version prompts for different models and use cases. For the AI/ML community this is significant because it centralizes prompt engineering artifacts that are otherwise scattered across forums and private repos. That improves reproducibility, speeds iteration on prompt-based pipelines, and creates a lightweight resource for benchmarking, prompt chaining, and rapid prototyping without fine-tuning. It also surfaces meta-rules (style guides, coding conventions, safety constraints) that can be integrated into multi-prompt workflows or used as instruction-tuning corpora. At the same time CTX raises governance questions — curation, moderation, model-compatibility and misuse mitigation — since powerful behavior-changing prompts can be shared widely. Overall, CTX looks like a practical commons for standardizing and accelerating real-world prompt engineering.